Drinking out of a paper cup

Wednesday

Aug 20, 2014 at 12:01 AMAug 20, 2014 at 10:15 AM

Alex Breitler/Record Staff Writer

California regulators over the past century have awarded rights to divert five times as much water as is actually available in the state’s rivers and streams, adding to the conflict over limited water supplies this summer, a new study finds.

The fact that there is more paper water than real water in California has been acknowledged for years.

But Tuesday’s study, published in the journal Environmental Research Letters, reveals which rivers are most oversubscribed.

Stockton’s own San Joaquin River leads the pack. The state has promised 861 percent more water to farms and cities than the San Joaquin actually provides, researchers at the University of California, Davis, reported.

The Stanislaus and Mokelumne rivers weigh in at 391 percent and 142 percent, respectively.

Most of the water was promised to public water agencies, including the state and federal governments that deliver water south of the Delta. A smaller amount of water was promised to corporations or individual landowners.

“It’s baffling to me,” said Ted Grantham, who worked on the study as a postdoctoral student at Davis and is now with the U.S. Geological Survey. “In some places it’s so obvious that water has been grossly overpromised. There’s no way junior water-right holders should be able to get water in most years.”

To some degree, it’s not abnormal for paper water rights to exceed the actual amount of water that is available.

Some water-right holders don’t use their full allocation, making more water available for others, the State Water Resources Control Board has said.

And in some cases, water diverted under a single water right can be used multiple times. For example, runoff from a farmer’s field can be diverted again farther downstream.

Still, California’s paper water eclipses its real water by an enormous 300 million acre-feet, the Davis researchers found. That’s enough to fill New Melones Lake, a relatively large reservoir, 125 times.

And that number may be underestimated, the researchers said, because it does not consider additional pumping by thousands of more senior water-right holders, including farmers whose fields are directly adjacent to a river or stream.

State regulators have only limited information about how much water is actually used. So the sheer number of paper water rights makes it difficult to determine who should be cut off in a year like this, when the shortage is particularly acute, the study finds.

Stockton environmentalist Bill Jennings, whose California Sportfishing Protection Alliance has documented the state’s over-allocation of water in the past, called again Tuesday for officials to determine once and for all how much water is really available and who should get it — a legal process known as “adjudication.”

“People down south have mortgaged their futures and hopes on false promises of water,” Jennings said.

Contact reporter Alex Breitler at (209) 546-8295 or abreitler@recordnet.com. Follow him at recordnet.com/breitlerblog and on Twitter @alexbreitler.